Drilling tool



July 31, 1951 c. E. WHITTAKER DRILLING TOOL Filed Oct. 19, 1945.INVENTOR. CHARLES E Mam/m? ATTOPA/f) Patented July 31, 1951 DRILLINGTOOL Charles E. Whittaker, Los Angeles County, Calif., assignor to GlobeOil Tools Company, Los Nietos, Calif., a corporation of CaliforniaApplication October 19, 194.5,Serial No. 623,237

7 Claims.

1 This invention has to do with a drilling tool and is primarilyconcerned with a tool operable to aid or supplement the action of adrilling bit, and it is a general object of the invention to provide asimple, practical, efiective tool acting to stabilize a bit and toassure a full sized well bore.

In drilling wells with the rotary method it is common to provide adrilling bit on the lower end of a drill string, usually on the end of adrill collar applied to a drill string, and as the bit is operated byrotating the drill string it is advanced into the formation and forms awell bore.

With the usual equipment, difiiculty is frequently experienced ingaining a straight full sized bore and, as a result, many operatorsresort to complicated and expensive devices such as wall scrapers,reamers, stabilizers, and like devices, in order to straighten the Wellbores and to assure the proper size of bore. Reamers are used above thebit when difficulties are encountered in keeping the hole out to gageand also as an aid in stabilizing the bit and drill collar. When it isdesired to stabilize only, the cutters of the reamer are replaced byrollers. In either case, it is not possible in practice to get thecutters or rollers closer to the bit than about four to five times thediameter of the hole being drilled.

It is a general object of my present invention to provide a drillingtool to be used in conjunction with an ordinary drilling bit, say forinstance, a roller bit, and which is operable to stabilize the drillingbit and also to cut the well bore, if necessary, to bring it to thedesired size. The tool of the present invention is preferablyproportioned to be slightly smaller in diameter than the well bit, andit is not located at a point remote from the bit but is very close abovethe bit so that it serves to stabilize close to thebit and also toassure a full sized bore to a point close to the bit. The hole engagingparts that I provide may be within two-thirds to three-quarters of thehole diameter from the bottom of the hole.

Another object of the present invention is to provide a tool in thenature of an insert or attachment applicable between a bit and adrilling string or a drill collar that does not require any change ormodification of the standard drilling equipment and which can beinserted or removed easily and quickly, as circumstances may require.

Another object of the present invention is to provide a tool of thegeneral character referred to in which the parts subject to wear aresimple and inexpensive and are readily replaceable,

.making it simple and inexpensive to maintain the .weli p r W k sem m.Teei e e the present invention involves a simple ring carrying cuttingteeth, which ring can be replaced as a unit by simply unthreading itfrom the main body, and in general this removable or replaceable part isvery simple and inexpensive as compared with the p'arts ordinarilrequired in well reaming devices which in and of themselves are usuallycomplicated mechanisms.

Another object of my inventionis to provide a tool of the characterdescribed having numerous closely spaced teeth which serve as eiiectivestabilizers whereas the'usual reamer, or like tool, has only three partsto engage the wall of the bore.

The various objects and features of my invention will be fullyunderstood from the followin detailed description of a typical preferredform and application of the invention, throughout which descriptionreference is made to the accompanying drawings, in which:

Fig. l is a side elevation of the lower end portion of a well drillingstring showing the lower end of a drill collar and a typical welldrilling bit with the tool provided by this invention inserted betweenthe collar and bit. Fig. 2 is an enlarged View of the tool of thepresent invention, showing it removed from the drill collar and showin'the bit in place and the lower end portion of the tool broken away toshow its construction and the manner in which the bit connects to it andFig. 3 is a sectional view of a part of the tool taken substantially asindicated by line 3-3 on Fig. 2.

The tool provided by this invention is useful, generally, in connectionwith the usual rotary drilling equipment and is particularly useful inconnection with the ordinary drilling bit, such as is operated by theusual well drilling string. In the drawings I have illustrated a typicalform of the present invention and have there shown a typical drillingbit A involving roller cutters and have shown the lower end portion of adrill collar B to which the bit is usually directly applied. In Fig. 1of the drawings I have shown the structure that I have provided insertedbetween the drill collar B and the bit A. In .fact, in Fig. 1 I haveshown two units of the present invention connected together or end toend, and inserted between the bit and drill collar, it beingunderstoodthat one or more units or tools such as I have provided may beused, as circumstances may require. In thefo'llowing description I willset forth the details of one typical unit of the presentinvention,fit.ibeingunderstood that such description will equally applyto the various units that may be used.

The bit A disclosed in the drawings is intended to illustrate merely atypical or conventional well drilling bit and I have. for example,illustrated a bit of the roller type wherein there is a body ID with aplurality of depending legs I I carrying suitable roller cutters I2. Atapered threaded pin l3 projects upwardly from the upper end of the bodyand is designed to fit into a threaded socket in the lower end of adrill collar, or the like.

The roller cutters I2, in accordance with conventional construction, arepitched, arranged and related to cut a hole or to form a bore of thedesired diameter, and they include cutting parts to act on the bottom ofthe bore, as well as parts to act on the side of the bore sufiicient tobring the bore to the desired diameter. In practice the parts of thecutters provided to define the diameter of the bore project radiallysomewhat beyond the legs I I and, in practice, these parts often weardown after a short period of use with the result that the bit does notform a bore or full diameter. In practice where a bore is under size andrequires reaming or if a new hit is introduced, the parts provided tomaintain the diameter of the bore have to ream as the bit is advancedthrough the previously established bore, and before it reaches bottom,all with the result that in many cases the bit may be somewhat undersize even before it advances the hole.

The drill collar B illustrated in Fig. 1 may be the usual heavy tubularbody commonly provided on the lower end of a drilling string and havinga tapered threaded socket in its lower end to rereceive the pin of a bitor the like.

The tool provided by my invention is in the nature of an insert to bearranged between a bit A and a drill collar B, or the like, and itinvolves, generally, a body C, a sleeve D detachable from the body, andcutters or teeth E carried by the sleeve.

The body is an elongate tubular element made sufficiently long to carrythe sleeve D in the manner hereinafter described and to present asurface that can be effectively engaged by suitable tools to facilitateits application to and removal from a position between the bit andcollar. Since the body C is inserted between the bit and collar it ispreferably formed at its ends to facilitate direct connection with thebit and collar and in an ordinary situation the body is provided in itslower end with a threaded tapered socket l5 shaped and proportioned toreceive the pin !3 of a bit A and it is provided at its upper end with atapered threaded pin H; to be received in the socket I! provided in thelower end of the drill collar B. It is to be understood that the means Ihave described for connecting the body to other elements may be variedand that I contemplate that such means may include intervening partssuch as subs, or the like. The lower end I8 is preferably fiat andnormal to the axis of the body so that the shoulder l9 formed at theupper end of the bit body In can be seated against it. The upper end 20of the body C is preferably made flat and normal to the longitudinalaxis of the body so that it can be seated against the lower end 2| ofthe collar B or the lower end of another body C as the case may be.

The body C of the tool that I have provided is formed with an enlargedportion 22 intermediate its ends which enlarged portion is shaped topresent a downwardly facing shoulder 23 and. a threaded portion 24 belowthe shoulder.

The threads of portion 24 are preferably coarse and 4 tapered and theshoulder 23 is preferably flat and normal to the longitudinal axis ofthe body. The lower end portion 25 of the body C which continues forsome distance below the threaded portion 24 is somewhat smaller indiameter than the small lower end of the threaded portion 24 so that thelower end portion of the body C is, in effect, somewhat reduced indiameter. The upper end portion 26 of the body C above the portion 22may be a straight turned part sufliciently long to accommodate tongs orother suitable tools and provided with suitable grooves or wickers 21 toaccommodate fishing equipment.

The body C has a circulation opening extending longitudinally through itso that it is, in effect, tubular and in the preferred form of theinvention the circulation opening 30 formed through the body C isenlarged at 3| intermediate its ends forming a chamber in the body. Aplurality of circulation distributing ports 32 extend from the chamberformed by the enlarged part 3| down and out through the body todischarge where the lower end of the threaded portion 24 joins thereduced lower end portion 25 of the body. Through this construction orformation of ports the major portion of the circulating fluid passes tothe bit A to act in the conventional manner, whereas the remainder or apart of the circulation fluid passes through the ports 32 to bedischarged downwardly at the lower end portion of the body 0.

The sleeve D that I have provided is preferably a plain or simple sleevehaving an upper end portion 40 internally threaded at 4| to receive thethreaded portion 24 of the body C. The upper end 42 of the sleeve ispreferably flat and forms a shoulder to engage or seat against theshoulder 23 of the body C. The lower end portion 45 of the sleeve Dcontinues downward from the threaded parts 24 and 4| to form a dependingskirt which surrounds the lower end portion 25 of the body C withclearance so that there is an annular port or duct 50 between the bodyand sleeve receiving circulating fluid from the ports 32 and dischargingdownwardly at a point close to the lower end of the body C. The lowerend portion 45 of the sleeve D continues downward to a point close tothe lower end of the body C.

The cutting teeth E may, in practice, vary in size, number and characterdepending upon the service to be performed. However, in the preferredconstruction I provide a multiplicity of teeth E substantially as shownin the drawings and each tooth has a bottom end portion 60 somewhatbelow the lower end of the body C and a vertical side part 6| extendingupwardly from the bottom 60 a substantial distance and to a pointsomewhat above the lower end 62 of the sleeve. The lower inner portions64 of the teeth may be bevelled off substantially as shown in thedrawings to provide clearance for the upper end portion of the bit bodyHi.

In accordance with my invention I preferably provide hard facing on thebottom portions 60 and the vertical side portions 6| of the teeth and Ishape and dress the teeth to effectively cut as the tool is rotated withthe bit. It will be understood that suitable cutting edges and thenecessary clearance may be provided by shaping and dressing the teeth.In practice the lower or bottom end portions 60 of the teeth can be oflimited radial extent. However, I prefer to make the side portions 6| ofconsiderable length so that they are effective in cutting the side ofthe well bore in order to have a reaming action in the crates and thebit A gets under size the cutters E act to ream the bore established bythe bit A.

By providing effective long cutting parts on the teeth E. the tool thatI have provided will serve to effectively ream immediately above the bitso that for all practical purposes the well bore is maintained fulldiameter to its bottom. It is to be observed that the presence of thetool that I have provided immediately above the bit not only causes thereaming action that I have described but further acts in the bore toeffectively stabilize the bit and thus facilitates the drilling of astraight hole. As the drilling operation progresses the drilling fluiddischarged by the ports 32 passes down through the annular chamber 5!!to discharge out at or between the teeth E and thus serves to keep theteeth clean and to prevent balling up such as might otherwise occur. Itis to be noted in particular that through the construction that I haveprovided the depending skirt portion 45 of the ring D with the teeth Eon its lower end portion establishes teeth at or around the upper end ofthe bit body 10. In fact, it is preferred that the teeth be extended sothat their lower ends 60 are actually below the upper end of the bitbody, thus bringing the reaming and stabilizing parts that I haveprovided to a point very close to the cutting parts of the bit A. It isto be noted that the lower ends of the teeth are not only below theshouldered connection between the bit and body but that the distancefrom the bottom of the teeth to the bottom of the bit is less than thediameter of the bit and consequently less than the diameter of the wellbore.

Having described only a typical preferred form and application of myinvention, I do not wish to be limited or restricted to the specificdetails herein set forth, but wish to reserve to myself any variationsor modifications that mayappear to those skilled in the art and fallwithin the scope of the following. claims.

Having described my invention, I claim:

1. A tool for insertion between a bit and a drilling string including,an elongate tubular body having means at its upper end making connectionwith the drilling string, threads in the lower end portion of the bodyreceiving and holding the bit, threads on the exterior of the body atthe lower end portion thereof, a sleeve surrounding the lower endportion of the body and held thereon by the last-mentioned threads,

an annular series of teeth on the sleeve projecting downwardly andradially outwardly therefrom and surrounding a portion of the bit to cutat the lower end of the body and having an outside diameter greater thanthat of the body.

2. A tool for insertion between a bit and a drilling string including,an elongate tubular body having means at its upper end making connectionwith the drilling string, threads in the lower end portion of the bodyreceiving and holding the bit, threads on the exterior of the body atthe lower end portion thereof, a sleeve surrounding the lower endportion of the body and depending therefrom, the sleeve being held onthe body by the last-mentioned threads, an

annular series of teeth depending from the sleeve and surrounding thebit adjacent thelower end of the body and projecting radially outwardfrom the sleeve to cut a bore larger than the body.

3. A tool for insertion betweena bit and a drilling string including, anelongate tubular body having means at its upper end making connectionwith the drilling string, threads in the lower end portion of the bodyreceiving and holding the bit, threads on the exterior of the body atthe lower end portion thereof, a downwardly facing shoulder on the bodyimmediately above the last-mentioned threads, a sleeve surrounding thelower end portion of the body and held thereon by the last-mentionedthreads with the upper end of the sleeve bearing against said shoulder,an annular series of teeth on the sleeve projecting downwardly andradially outwardly therefrom and surrounding a portion of the bit to cutat the lower end of the body and having an'outside diameter greater thanthat of the body.

4. A tool for insertion between a bit and drilling string including, atubular body having means at one end for connecting it to the string andmeans at the other end for connecting it to the bit, there being adownwardly facing shoulder on the body intermediate its ends, a sleevethreaded on the body at the exterior thereof and bearing against theshoulder and having a depending skirt portion projecting below the endof the body to which the bit is attached and cooperating with the bodyto define an annular space, and teeth on the skirt projecting downwardlytherefrom and also. radially outward therefrom to cut a bore larger thanthe body and to overlie the bit adjacentthe body, the body having acirculation opening communicating with said annular space.

5. A tool for insertion between a bit and drilling string including, atubular body having means at its upper end for connecting it to thestring, means at its lower end for connecting it to the bit and anenlarged part intermediate its ends with a downwardly facing shoulder, asleeve on the exterior of the body bearing up against the shoulder andhaving a lower end portion spaced from the body forming a chamber, thebody having a circulation port communicating with said chamber, andteeth on said lower end portion of the sleeve projecting radiallyoutward and also axially beyond the lower end of the body. 1

CHARLES E. WHITTAKER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

